Toy sewing machine capable of switching between zigzag stitch forming and straight stitch forming operations

ABSTRACT

A toy sewing machine capable of switching between zigzag stitch forming and straight stitch forming operations comprising a machine body, a rotary main shaft, a needle bar mounting a sewing needle and connected to said rotary main shaft for reciprocating motion in a vertical plane, a pivotal member connected to said machine body for pivotal motion in a horizontal plane and formed with an axial center bore for permitting said needle bar to loosely extend therethrough, an actuation bar connected to said pivotal member for reciprocating motion in a horizontal plane, oscillating mechanism for causing said actuation bar to move in reciprocating motion in a horizontal plane in conjunction with the reciprocating motion of said needle bar, a mechanism for switching between a zigzag stitch forming operation and a straight by controlling the engagement of said actuation bar with said oscillating mechanism, a swinging mechanism connected to said actuation bar for repeated angular rotation to right and left as said actuation bar moved in reciprocating motion in a horizontal plane, a looper shaft connected to said swinging mechanism for reciprocating motion in a horizontal plane as said swinging mechanism repeatedly rotates angularly and a looper mounted at said looper shaft for cooperation with said needle.

United States Patent [72] Inventor Sakae Kasai Nakakoma-gun, Japan [21]AppLNo. 47,671 i [22] Filed June 19, 1970 [45] Patented Jan. 11, 197273] Assignee Crystal Sewing Machine Ind. Co., Ltd.

Tokyo, Japan [32] Priorities June 26, 1969 [33] Japan June 26, 1969,Japan, No. 44/60011 [54] TOY SEWING MACHINE CAPABLE OF SWITCHING BETWEENZIGZAG STITCH FORMING AND STRAIGHT STITCH FORMING OPERATIONS 2 Claims, 3Drawing Figs.

[52] US. Cl 112/159 [50] Field ofSearch 112/159 [56] References CitedUNITED STATES PATENTS 986,354 3/1911 Brown 112/159 2,028,016 1/1936Schweiger... 112/159 2,045,340 6/1936 Bolter 112/159 2,690,723 10/1954Sudo Primary Examiner-Richard J. Scanlan, Jr. Altorne vStevens, Davis,Miller & Mosher ABSTRACT: A toy sewing machine capable of switchingbetween zigzag stitch forming and straight stitch forming operationscomprising a machine body, a rotary main shaft, a needle bar mounting asewing needle and connected to said rotary main shaft for reciprocatingmotion in a vertical plane, a pivotal member connected to said machinebody for pivotal motion in a horizontal plane and formed with an axialcenter bore for permitting said needle bar to loosely extendtherethrough, an actuation bar connected to said pivotal member forreciprocating motion in a horizontal plane, oscillating mechanism forcausing said actuation bar to move in reciprocating motion in ahorizontal plane in conjunction with the reciprocating motion of saidneedle bar, a mechanism for switching between a zigzag stitch formingoperation and a straight by controlling the engagement of said actuationbar with said oscillating mechanism, a swinging mechanism connected tosaid actuation bar for repeated angular rotation to right and left assaid actuation bar moved in reciprocating motion in a horizontal plane,a looper shaft connected to said swinging mechanism for reciprocatingmotion in a horizontal plane as said swinging mechanism repeatedlyrotates angularly and a looper mounted at said looper shaft forcooperation with said needle.

2Q w 34 Ezra 4 j so 3 I m 32 PATENTED JAN! 1 I972 A TTORNE Y 5 TOYSEWING MACHINE CAPABLE OF SWITCHING BETWEEN ZIGZAG STITCH FORMING ANDSTRAIGHT STITCH FORMING OPERATIONS This invention relates to toy sewingmachines which are capable of switching between zigzag stitch formingand straight stitch forming operations. More particularly, the inventionis concerned with a toy sewing machine which is provided with means forswitching between a zigzag stitch forming operation and a straightstitch forming operation, and means for synchronizing the operation ofan elevational needle bar and a looper.

An object of this invention is to provide a toy sewing machine which isprovided with a mechanism for switching between zigzag stitch formingand straight stitch forming operations comprising a pivotal memberpivotally movable in a horizontal plane and formed with an axial centerbore through which loosely extends an elevational needle bar connectedto a rotary main shaft and adapted to move in reciprocating motion in avertical plane, an actuation bar con nected at one end thereof to a freeend of the pivotal member and capable of moving in reciprocating motionin a horizontal plane parallel to the machine body, said actuation barbeing urged to move in one direction in a horizontal plane by a springand adapted to engage at the other end thereof an oscillating membercoupled to the rotary main shaft for oscillating motion so as to permitthe actuation bar to move in reciprocating motion in a horizontal plane,and means for controlling the engagement of the other end of theactuation bar with the oscillating member.

Another object of the invention is to provide a toy sewing machineprovided with means for synchronizing the operations of the elevationalneedle bar and a looper which permits a looper shaft to operate insynchronism with the operation of the actuation bar adapted to move inreciprocating motion in a horizontal plane in conjunction with thereciprocating motion of the elevational needle bar.

Additional objects as well as features and advantages of the presentinvention will become evident from the description set forth hereinafterwhen considered in conjunction with the accompanying drawings, wherein:

FIG. I is a schematic side view of the toy sewing machine according tothis invention in explanation thereof;

FIG. 2 is a plan view of the toy sewing machine of FIG. 1; and

FIG. 3 is a sectional view along the line IIIIII ofFIG. l.

The toy sewing machine as shown in the drawings comprises a machine body1 which mounts a main shaft 2 driven by a suitable drive means forrotation in a predetermined direction. Connected to one end of the mainshaft 2 through a crank mechanism 3 is a needle bar 4 which is adaptedto move in reciprocating motion in a vertical plane with respect to themachine body 1. The needle bar 4 is loosely fitted in a vertical axialcenter bore formed in a pivotal member 6 supported by a supporting shaft5 secured to the machine body 1 for pivotal motion in a horizontalplane. The pivotal member 6 is formed on one side thereof with aprojection which serves as a connecting portion 7 for pivotallysupporting, through a pin 9, one end of an actuation bar 8 mounted inparallel relation with the main shaft 2. The actuation bar 8 issupported near the other end thereof by an oscillating member 10.

The oscillating member 10 which is supported by a shaft 11 secured tothe machine body I for oscillating motion in a horizontal plane isformed in its central portion with a cam opening 12 which receivestherein an eccentric cam 13 supported by the shaft of a gear 14 which ismaintained in meshing engagement with a crown gear 15 mounted on themain shaft 2.

Provided on the upper surface of the end portion of the oscillatingmember 10 which supports the actuation bar 8 near the other end thereofis a pin 16 which is received in a guide opening 17 formed in theactuation bar 8 near the other end thereof. The guide opening 17consists of an opening section 17' for a straight stitch formingoperation which has a major dimension portion extending axially or in adirection of horizontal reciprocating motion of the actuation bar 8 andcurved slightly arcuately to conform to the locus of movement of the pin16, and an opening section 17 for a zigzag stitch forming operationwhich has a major dimension portion disposed at right angles to thelongitudinal axis of the actuation bar on one side of the openingsection 17' and contiguous therewith, the opening sections 17' and 17"being arranged substantially in T-shape.

A spring 18 connected at one end to the machine body 1 is connected atthe other end to one side of the actuation bar 8 so as to normally urgethe actuation bar 8 to rotate about the shaft 9 in the direction of anarrow 19.

The actuation bar 8 is formed on the other side of the other end thereofwith a concaved surface portion 20, convexed surface portion 21 andbeveled surface portion 22 interposed between the two surface portions20 and 21. The three surface portions function as switching operationsurfaces.

A switching cam 24 rotatably supported by a shaft secured to the machinebody 1 and provided with a knob 23 is disposed against the surfaces 20,21 and 22.'Mounted to the machine body 1 is a swinging shaft 25 whichsupports at its upper end one end of an oscillating plate 26 which isadapted to move in oscillating motion in a horizontal plane. Provided onthe upper surface of the other end of the oscillating plate 26 is a pin27 which is received in a slot 28 formed in the actuation bar 8 andarranged with its major dimension portion disposed at right angles tothe longitudinal axis of the actuation bar 8. Provided at the lower endportion of the swinging shaft 25 is a crank member 29 which is formedwith a projection 29' engageably received in a groove 31' of a groovedpulley 31 firmly secured to a looper rotating shaft 30 mounted below themachine body 1 for reciprocating motion in a horizontal direction. Theshaft 30 is connected to the main shaft 2 through a gear train,consisting of gears 32, 34, 36, 38 to be driven thereby.

The operation of the present invention will now be described. As shownin FIG. 2, the pin 16 provided on the oscillating member 10 is normallyreceived in the opening section 17" of the guide opening 17 because theoperation bar 8 is urged to move in the direction of the arrow 19 by thebiasing force of the spring 18. The switching cam 24 is maintained inengagement with the concaved surface portion 20 of the actuation bar 8.

If the main shaft 2 is rotated at this time, the needle bar 4 is causedby the crank 3 to move in reciprocating motion in a vertical plane withrespect to the machine body 1 while loosely extending through the axialcenter bore formed in the pivotal member 6. At the same time, therotation of the main shaft 2 is transmitted through the crown gear 15 tothe eccentric cam 13 which presses against the inner wall of the camopening 12, so that the oscillating member 10 moves in oscillatingmotion about the shaft 11, thereby causing the actua tion bar 8 to movein reciprocating motion in a horizontal plane in a predetermined stroke.The reciprocating movements of the actuation bar 8 cause the pivotalmember 6 connected to the actuation bar to move in pivotal motion aboutthe supporting shaft 5 in a horizontal plane. This permits the needlebar 4, which is moving in reciprocating motion in a vertical plane, tomove simultaneously in pivotal motion such that it causes the needle toform zigzag stitches instead of straight stitches.

Simultaneously as the actuation bar 8 moves in reciprocating motion, theoscillating plate 26 moves in oscillating motion about the swingingshaft 25 so as to cause the swinging shaft 25 to rotate angularly toright and left repeatedly in synchronism with the reciprocating motionof the actuation bar 8. The crank member 29 at the lower end of theshaft 25 causes the looper shaft 30 to move in reciprocating motion toright and left in FIG. 1 in a horizontal plane. It will thus be evidentthat the elevational needle bar 4 and the looper shaft 30 are moved insynchronism with the reciprocating motion of the needle bar 4 such thatthe forward end of the looper 33 crosses the needle 34 on the needle bar4 at the same position at all times, thereby permitting to form zigzagstitches in the most appropriate manner.

The operation of switching from zigzag stitch forming to straight stitchforming will now be explained. If the knob 23 is operated to shift theswitching cam 24 from a position in which it is in engagement with theconcave portion through the beveled surface portion 22 to a position inwhich it is maintained in engagement with the convexed surface portion21, then the actuation bar 8 moves in pivotal motion about thesupporting shaft 9 in a direction opposite to the direction of the arrow19 against the biasing force of the spring 18, thereby bringing the pin16 on the oscillating member 10 into engagement in the opening section17' whose major dimension portion is disposed parallel to thelongitudinal axis of the actuation bar 8. Accordingly, when theoscillating member 10 moves in oscillating motion, the pin 16 moves inidling motion, so that no motion is transmitted to the actuation bar 8in spite of the oscillating movements of the oscillating member 10. Thisresults in the needle bar 4 merely moving in a reciprocating motion in avertical plane permitting the needle 34 to form straight stitches.

From the foregoing description, it will be appreciated that the presentinvention makes it possible to maintain the needle and looper at properrelative positions at all times since means is provided to bring thereciprocating movements of the actuation bar or the oscillatingmovements of the needle bar for permitting the needle bar to perform azigzag stitch forming operation into synchronism with the reciprocatingmovements of the looper shaft. The synchronizing means of this inventionis highly efficient and yet simple construction for use with toy zigzagsewing machines.

What is claimed is:

1. A sewing machine, especially suited as a toy sewing machine, capableof forming straight or zigzag stitching, comprising: a main rotary driveshaft drivingly engaged with a reciprocating needle bar, a rotary loopershaft for cooperating with said needle bar to sew stitches, said driveshaft being arranged to rotate said looper shaft and to reciprocate saidneedle bar synchronously with each other, and oscillatory means tooscillate said needle bar in a plane perpendicular to its direction ofreciprocation and to correspondingly oscillate said looper shaft so asto sew zigzag stitches, said oscillatory means comprising a rotary camdriven by said main shaft, a first member adapted to be acted on by saidcam to oscillate in a said plane and connected to said needle bar andalso to said looper shaft so as to correspondingly oscillate said needlebar and looper shaft, a single actuation means for selectivelyeffectively connecting of disconnecting said first member relative tosaid cam whereby actuation of said single actuation means by theoperator renders operable or inoperable said oscillatory meanssimultaneously relative to said needle bar and said looper shaft, saidoscillatory means including a T- shaped slot and a pin, said firstmember being connected to said cam by means of said pin engaging saidT-shaped slot, said actuation means being adapted to shift said firstmember relative to said pin so that said pin is engaged in one or theother legs forming said T-shaped slot, one of said legs extendingparallel to said plane of oscillatory movement whereby no movement istransmitted to said first member by said cam when said pin is engaged insaid one leg, and the other leg extending perpendicular to said plane ofoscillatory movement whereby movement is transmitted form said cam tosaid first member when said pin is engaged in said other leg.

2. A toy sewing machine capable of switching between zigzag stitchforming and straight stitch forming operations comprising a machinebody, a rotary main shaft rotatably secured to said machine body, aneedle bar mounting a sewing needle at its forward end and connected tosaid rotary main shaft for reciprocating motion in a vertical plane withrespect to said machine body, a pivotal member connected to said machinebody for pivotal motion in a horizontal plane and formed with an axialcenter bore for permitting said needle bar to loosely extendtherethrough, an actuation bar connected at one end thereof to the freeend of said pivotal member for oscillating motion of said pivotal memberin a horizontal plane, oscillating mechanism for causing said actuationbar to move in reciprocating motion in a horizontal plane along itslongitudinal axis in conjunction with the reciprocating motion of saidneedle bar in a vertical plane, a mechanism for switching between azigzag stitch forming operation and a straight stitch forming operationby controlling the engagement of said actuation bar with saidoscillating mechanism, a swinging mechanism connected to said actuationbar near the other end thereof for repeated angular rotation to rightand left as said actuation bar moves in reciprocating motion in ahorizontal plane, a looper shaft mounted below the machine body andconnected to said swinging mechanism for reciprocating in a horizontalplane as said swinging mechanism repeatedly rotates angularly to rightand left, and a looper mounted at the forward end of said needle bar,wherein said mechanism for switching between a zigzag stitch formingoperation and a straight stitch forming operation by controlling theengagement of said actuation bar with said oscillating mechanismcomprises an oscillating member and a spring, said spring urging saidactuation bar to move in a horizontal direction transverse of itsreciprocating motion; by its biasing force, a pin provided on saidoscillating member a T-shaped opening formed in said actuation bar nearsaid free end thereof and consisting of a first opening section with itsmajor dimension portion extending along the longitudinal axis of theactuation bar and a second opening section with its major dimensionportion extending at right angles to the longitudinal axis of theactuation bar, said two opening sections being adapted to receive saidpin selectively, an engaging surface formed on one side of the free andportion of said actuation bar and consisting of a concaved surfaceportion, beveled surface portion and convexed surface portion, andswitching cam adapted to move said actuation bar against said springbiasing force and relative to said pin by engaging one of said concavedand con-,

vexed surface portions thereby to selectively cause said pin to bereceived in said first or said second opening section.

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1. A sewing machine, especially suited as a toy sewing machine, capableof forming straight or zigzag stitching, comprising: a main rotary driveshaft drivingly engaged with a reciprocating needle bar, a rotary loopershaft for cooperating with said needle bar to sew stitches, said driveshaft being arranged to rotate said looper shaft and to reciprocate saidneedle bar synchronously with each other, and oscillatory means tooscillate said needle bar in a plane perpendicular to its direction ofreciprocation and to correspondingly oscillate said looper shaft so asto sew zigzag stitches, said oscillatory means comprising a rotary camdriven by said main shaft, a first member adapted to be acted on by saidcam to oscillate in a said plane and connected to said needle bar andalso to said looper shaft so as to correspondingly oscillate said needlebar and looper shaft, a single actuation means for selectivelyeffectively connecting of disconnecting said first member relative tosaid cam whereby actuation of said single actuation means by theoperator renders operable or inoperable said oscillatory meanssimultaneously relative to said needle bar and said looper shaft, saidoscillatory means including a T-shaped slot and a pin, said first memberbeing connected to said cam by means of said pin engaging said T-shapedslot, said actuation means being adapted to shift said first memberrelative to said pin so that said pin is engaged in one or the otherlegs forming said T-shaped slot, one of said legs extending parallel tosaid plane of oscillatory movement whereby no movement is transmitted tosaid first member by said cam when said pin is engaged in said one leg,and the other leg extending perpendicular to said plane of oscillatorymovement whereby movement is transmitted form said cam to said firstmember when said pin is engaged in said other leg.
 2. A toy sewingmachine capable of switching between zigzag stitch forming and straightstitch forming operations comprising a machine body, a rotary main shaftrotatably secured to said machine body, a needle bar mounting a sewingneedle at its forward end and connected to said rotary main shaft forreciprocating motion in a vertical plane with respect to said machinebody, a pivotal member connected to said machine body for pivotal motionin a horizontal plane and formed with an axial center bore forpermitting said needle bar to loosely extend therethrough, an actuationbar connected at one end thereof to the free end of said pivotal memberfor oscillating motion of said pivotal member in a horizontal plane,oscillating mechanism for causing said actuation bar to move inreciprocating motion in a horizontal plane along its longitudinal axisin conjunction with the reciprocating motion of said needle bar in avertical plane, a mechanism for switching between a zigzag stitchforming operation and a straight stitch forming operation by controllingthe engagement of said actuation bar with said oscillating mechanism, aswinging mechanism connected to said actuation bar near the other endthereof for repeated angular rotation to right and left as saidactuation bar moves in reciprocating motion in a horizontal plane, alooper shaft mounted below the machine body and connected to saidswinging mechanism for reciprocating in a horizontal plane as saidswinging mechanism repeatedly rotates angularly to right and left, and alooper mounted at the forward end of said needle bar, wherein saidmechanism for switching between a zigzag stitch forming operation and astraight stitch forming operation by controlling the engagement of saidactuation bar with said oscillating mechanism comprises an oscillatingmember and a spring, said spring urging said actuation bar to move in ahorizontal direction transverse of its reciprocating motion; by itsbiasing force, a pin provided on said oscillating member a T-shapedopening formed in said actuation bar near said free end thereof andconsisting of a first opening section with its major diMension portionextending along the longitudinal axis of the actuation bar and a secondopening section with its major dimension portion extending at rightangles to the longitudinal axis of the actuation bar, said two openingsections being adapted to receive said pin selectively, an engagingsurface formed on one side of the free and portion of said actuation barand consisting of a concaved surface portion, beveled surface portionand convexed surface portion, and switching cam adapted to move saidactuation bar against said spring biasing force and relative to said pinby engaging one of said concaved and convexed surface portions therebyto selectively cause said pin to be received in said first or saidsecond opening section.